9,009 research outputs found
Perspectives about adult sibling relationships: a dyadic analysis of siblings with and without intellectual and developmental disabilities.
Most siblings of individuals with intellectual and developmental disabilities (IDD) report positive sibling relationships. However, extant research often only examines the perspective of the nondisabled sibling; it is unclear whether siblings with IDD report close sibling relationships. Thus, the aim of this study was to understand adult sibling relationships from the perspectives of both siblings with and without IDD. Using dyadic interviews, we examined the perspectives of eight adult sibling dyads. The study was conducted in the United States. Data were analyzed using constant comparative analysis and cross-case analysis to identify themes within and across dyads. Overall, siblings with and without IDD reported enjoying spending time with one another. However, siblings with and without Down syndrome (versus autism spectrum disorder) reported more reciprocal sibling relationships, more frequent contact, and a greater range of shared activities. Implications for future research and practice are discussed.Accepted manuscrip
The anatomy of the Gunn laser
A monopolar GaAs Fabry–Pérot cavity laser based on the Gunn effect is studied both experimentally and theoretically. The light emission occurs via the band-to-band recombination of impact-ionized excess carriers in the propagating space-charge (Gunn) domains. Electroluminescence spectrum from the cleaved end-facet emission of devices with Ga1−xAlxAs (x = 0.32) waveguides shows clearly a preferential mode at a wavelength around 840 nm at T = 95 K. The threshold laser gain is assessed by using an impact ionization coefficient resulting from excess carriers inside the high-field domain
Understanding decision making among individuals With Intellectual and Developmental Disabilities (IDD) and their siblings
Many siblings anticipate fulfilling caregiving roles for their brothers and sisters with
intellectual and developmental disabilities (IDD). Given these roles and the importance of
supported decision-making, it is crucial to understand how individuals with IDD and their
siblings make decisions. Using dyadic interviews, we examined the perspectives of nine sibling dyads (N = 18) about decision-making in relation to self-determination, independent living, and employment. The ages of participants ranged from 19 to 57. Data were analyzed using constant comparative analysis to identify themes. Decision-making was characterized by: parents and siblings primarily identifying courses of action; the probability of respective consequences based on the person-environment fit; and the role of the sibling in making the final decision. Characteristics related to the individual with IDD, the family, the sibling, and the environment impacted decision-making. Individuals with IDD were more likely to make their own decisions about leisure activities, however, siblings were more likely to make formal decisions for their brothers and sisters.Accepted manuscrip
Electro-kinetic technology as a low-cost method for dewatering food by-product
Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food byproducts that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This has brought about the necessity of dewatering food waste for any potential re-use for certain disposal options. A laboratory system for experimentally characterizing electro-kinetic dewatering of food by-products was evaluated. The bench scale system, which is an augmented filter press, was used to investigate the dewatering at constant voltage. Five food by-products (brewer’s spent grain, cauliflower trimmings, mango peel, orange peel, and melon peel) were studied. The results indicated that electro-kinetic dewatering combined with mechanical dewatering can reduce the percentage of moisture from 78% to 71% for brewer’s spent grain, from 77% to 68% for orange peel, from 80% to 73% for mango peel, from 91% to 74% for melon peel, and from 92% to 80% for cauliflower trimmings. The total moisture reduction showed a correlation with electrical conductivity (R2¼0.89). The energy consumption of every sample was evaluated and was found to be up to 60 times more economical compared to thermal processing
Parity Violation in Bottom Quark Pair Production at Polarized Hadron Colliders
Parity violation induced by the chromo-anapole form factor of the bottom
quark, generated from weak corrections, is studied in polarized hadron
collisions. The forward-backward asymmetry in the bottom quark pair production
at polarized and colliders is evaluated in the Standard Model
and in a Two Higgs Doublet Model to examine the effects of parity violation. In
the models studied, promising results are found for polarized
colliders.Comment: To be published in Physics Letters B, 3 references adde
Bino Dark Matter and Big Bang Nucleosynthesis in the Constrained E6SSM with Massless Inert Singlinos
We discuss a new variant of the E6 inspired supersymmetric standard model
(E6SSM) in which the two inert singlinos are exactly massless and the dark
matter candidate has a dominant bino component. A successful relic density is
achieved via a novel mechanism in which the bino scatters inelastically into
heavier inert Higgsinos during the time of thermal freeze-out. The two massless
inert singlinos contribute to the effective number of neutrino species at the
time of Big Bang Nucleosynthesis, where the precise contribution depends on the
mass of the Z' which keeps them in equilibrium. For example for mZ' > 1300 GeV
we find Neff \approx 3.2, where the smallness of the additional contribution is
due to entropy dilution. We study a few benchmark points in the constrained
E6SSM with massless inert singlinos to illustrate this new scenario.Comment: 24 pages, revised for publication in JHE
A preferential attachment model with random initial degrees
In this paper, a random graph process is studied and its
degree sequence is analyzed. Let be an i.i.d. sequence. The
graph process is defined so that, at each integer time , a new vertex, with
edges attached to it, is added to the graph. The new edges added at time
t are then preferentially connected to older vertices, i.e., conditionally on
, the probability that a given edge is connected to vertex i is
proportional to , where is the degree of vertex
at time , independently of the other edges. The main result is that the
asymptotical degree sequence for this process is a power law with exponent
, where is the power-law exponent
of the initial degrees and the exponent predicted
by pure preferential attachment. This result extends previous work by Cooper
and Frieze, which is surveyed.Comment: In the published form of the paper, the proof of Proposition 2.1 is
incomplete. This version contains the complete proo
Diffusive behavior for randomly kicked Newtonian particles in a spatially periodic medium
We prove a central limit theorem for the momentum distribution of a particle
undergoing an unbiased spatially periodic random forcing at exponentially
distributed times without friction. The start is a linear Boltzmann equation
for the phase space density, where the average energy of the particle grows
linearly in time. Rescaling time, the momentum converges to a Brownian motion,
and the position is its time-integral showing superdiffusive scaling with time
. The analysis has two parts: (1) to show that the particle spends
most of its time at high energy, where the spatial environment is practically
invisible; (2) to treat the low energy incursions where the motion is dominated
by the deterministic force, with potential drift but where symmetry arguments
cancel the ballistic behavior.Comment: 55 pages. Some typos corrected from previous versio
Production of CP-Odd Higgs Bosons with Large Transverse Momentum at Hadron Supercolliders
A two Higgs doublet model is employed to study the production of a CP-odd
Higgs boson () associated with a large transverse momentum jet () at
hadron supercolliders. The cross section of is evaluated with
four subprocesses: , , and
. We find that is a significant source of CP-odd
Higgs bosons at future hadron supercolliders.Comment: 17 pages in LaTeX, revised January 1994, to be published in Physics
Letters B, FSU-HEP-93092
Asymptotics for Duration-Driven Long Range Dependent Processes
We consider processes with second order long range dependence resulting from
heavy tailed durations. We refer to this phenomenon as duration-driven long
range dependence (DDLRD), as opposed to the more widely studied linear long
range dependence based on fractional differencing of an process. We
consider in detail two specific processes having DDLRD, originally presented in
Taqqu and Levy (1986), and Parke (1999). For these processes, we obtain the
limiting distribution of suitably standardized discrete Fourier transforms
(DFTs) and sample autocovariances. At low frequencies, the standardized DFTs
converge to a stable law, as do the standardized sample autocovariances at
fixed lags. Finite collections of standardized sample autocovariances at a
fixed set of lags converge to a degenerate distribution. The standardized DFTs
at high frequencies converge to a Gaussian law. Our asymptotic results are
strikingly similar for the two DDLRD processes studied. We calibrate our
asymptotic results with a simulation study which also investigates the
properties of the semiparametric log periodogram regression estimator of the
memory parameter
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